Understanding Your Baby's Quirks

You couldn't love them more, but your little cutie also does a thing or two that makes you say "huh?" Here's the reason behind some of their funniest and most adorable little quirks.

twin baby legs

Babies are incredible. They're also a little strange. All babies have quirks. Learn about some of the most common (and most adorable) ones with this guide.

01 of 13

Why Babies Smell So Good

cute baby smiling
Alexandra Grablewski

Two words: cleaner sweat. The apocrine glands⁠—which are found in the armpits, breasts/chest, and groin, and are associated with strong body odor⁠—aren't active until puberty. Also, your baby's scent is familiar to you, so it smells good.

Each of us has an "odor print" that's as individual as a fingerprint, according to the late George Preti, Ph.D., a chemist who studied human body odor at the Monell Chemical Senses Center in Philadelphia. Some parents can recognize their newborn by scent alone, and scientists think it could be because their olfactory cues circulate in the bloodstream during pregnancy. Early exposure makes the scent appealing.

02 of 13

Why Babies Suck on Their Toes

baby sucking toe
Alexandra Grablewski

Your little one learns about the objects around them (including those tiny toes) by putting them in their mouth. Nerve fibers in the mouth are more sensitive than those in the fingers. When your baby sucks on their body parts they experience a wide variety of fascinating touch sensations, says Ross Thompson, Ph.D., a professor of psychology at the University of California, Davis.

While babies love to suck anything they can get their lips on⁠—toys, TV remote⁠s, receiving blankets—many 4- and 5-month-olds simply find it easier to put their feet in their mouths.

03 of 13

Why Baby's Nails Grow So Fast

baby fingernails
Alexandra Grablewski

You aren't imagining it: Your baby's nails are actually growing twice as fast as your own. But there's a simple reason behind it: A child's metabolic rate is higher than that of adults, which means their skin cells (those that make up the composition of their nails) turn over more quickly, says Bernard Cohen, M.D., the director of pediatric dermatology at Johns Hopkins University in Baltimore.

Remember to keep your baby's nails trimmed so they don't cut themselves accidentally!

04 of 13

Why Babies Startle So Often

baby reaching
Fancy Photography/Veer

All healthy newborns are born with an evolutionarily programmed, involuntary impulse called the Moro reflex. If your baby is startled by a siren, car horn, or other loud sound, they'll fling their arms wide, spread their fingers, and instinctively ⁠grab at something (usually you). Then they'll bring their arms back to their body and relax.

"Newborns haven't yet learned to differentiate between common and uncommon noises," explains Richard Polin, M.D., a pediatrician and neonatal care expert at Columbia University in New York City. As your baby matures, their brain will learn to distinguish between different types of sound and movement, and this primitive reflex will be squelched.

05 of 13

Why Babies Hit and Scratch at Pictures in Books

baby holding book
Fancy Photography/Veer

Babies are used to seeing things in 3D, says Sue Hespos, Ph.D., principal investigator for the Infant Cognition Lab at Northwestern University in Evanston, Illinois. When your baby sees a 2D picture like in a book, they don't know what to do with it at first. (Can I pick it up? Play with it?) As you continue to read to them, however, their cognitive skills will develop, and they'll stop trying to palm Clifford the Big Red Dog.

06 of 13

Why Babies Hiccup

cute baby
Fancy Photography/Veer

Hiccups are caused by an involuntary contraction of the diaphragm, though why they occur so often in babies isn't totally known. Some experts think it can happen when babies eat too much or gulp down too much air while eating (something that you may see when the nipple on their bottle is too large, or they find themselves dealing with a gush of milk while nursing).

The good news is that hiccups aren't harmful or uncomfortable for your baby, and they will go away on their own.

07 of 13

Why Babies Thump Their Head on the Bed at Night

baby lying down
Fancy Photography/Veer

Head-thumping can be a baby's way of lulling themselves to sleep, says Tanya Altmann, M.D., a Los Angeles-based pediatrician and author of the book Baby & Toddler Basics. While it may look scary to you, it's usually nothing to worry about; in fact, studies show that up to 15% of healthy children do it (though it's three times more common in boys).

The thumping typically starts when babies are around 8 months old; only 5% of children will do it for more than a few months. If a child head-bangs after their first birthday, experiences a language delay, or avoids eye contact, talk to your pediatrician.

08 of 13

Why Babies Wrap Their Fingers Around Yours

baby finger wrap
Alexandra Grablewski

It's their way of showing you love. Starting at 3 or 4 months, your baby is able to hold onto your fingers, and they may do it every chance they get, such as when you're feeding or snuggling them. They also get a kick out of hearing your voice, so another great way to bond is to talk or sing to them.

09 of 13

Why Babies Drool

baby drooling
Fancy Photography/Veer

Infants have an immature nervous system, and they don't have as much control over their mouths as older children and adults, says Eve Colson, M.D., a professor of pediatrics at Washington University School of Medicine in St. Louis. Sure, your shoulder may get soaked when you carry them, but the drool won't last forever: It typically lessens by the end of the first year.

10 of 13

Why Babies Have "Frog Legs" When They Sleep

baby sleeping
Alexandra Grablewski

"Frog legs" just might be one of the cutest baby quirks and also one of the strangest. It turns out that this "frog legs" position is super familiar for your baby. During the first month or two of life, their arms, legs, elbows, and knees will be bent when they doze, much like they were in the womb. As their nervous system matures, their legs will straighten and they'll sleep in a looser position, says Dr. Polin.

11 of 13

Why Babies Love Playing Peekaboo

woman playing peek-a-boo with baby
BananaStock/ Jupiter

It makes them giggle! There's also the element of surprise, the fact that they're learning about object permanence, and the joys of attention from their caregiver. But don't bother playing peekaboo before they're 6 months old, because they won't be able to pay attention long enough to enjoy it, says Dr. Thompson.

12 of 13

Why Babies Sneeze

baby girl in jacket with eyes closed

Sneezing is a fallback mechanism, says Dr. Polin. Since your little one is too young to blow their nose, the only way they can get rid of mucus, dust, and other irritants stuck in their schnoz is to sneeze. Worried all those achoos signal an illness? Unless your baby spikes a fever or has trouble eating, they are probably fine.

13 of 13

Why Your Baby's Legs Sometimes Make a Clicking Sound

twin baby legs

It can be unnerving to hear a clicking noise from your baby, or to feel this movement in their legs, but it's probably just sliding tendons. This common phenomenon occurs when soft tissues (tendons) interact with hard tissues (bones). It's actually quite normal for a baby's body to make clicking and popping noises (like the sound of knuckles cracking), especially around the spine, shoulders, knees, and ankles.

If your baby makes these sounds in their hips, however—and if you hear a "clunk" rather than a "click"—talk to your pediatrician. You'll want to make sure they don't have a congenital hip dislocation, which should be treated ASAP.

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